Character Classes

gr[ea]y matches "grey", and "gray".

h[1-6] matches "h1", "h2", "h3", and so on, till "h6".

Multiple dash shorthands can be used, eg. h[1-6a-z].

Dash (-) is a metacharacter within a character class if it's not the first character in the character class. eg. h[-a-z], will match "h-"

Caret (^) can be used to create negated character classes. eg. h[^1-5] will not match "h1" to "h5".